1. Field of the Invention
This invention relates generally to a wedge for holding a tool head on a tool handle and more specifically to a wedge for a tool handle having a simple wedge in one direction with wing wedges formed at each end thereof.
2. Discussion of the Background
Many common hand tools, especially impact tools or swing tools, are formed from a metal head mounted on a wooden handle, with the handle fitting into an eye of the head. A wedge is often driven into the handle in order to expand the handle end against the inside of the eye to firmly hold the head in place.
Such an arrangement can have many disadvantages. In some case, the handle is subject to breakage near the junction of the tool head. The action of the wedge may cause the handle to split or be otherwise weakened. The impact on the tool head as it is used often can cause such stress that the handle may be damaged. Especially in large tools, it is very difficult to keep the head firmly attached to the handle because of the large impact. This may create a dangerous situation where the head can fly off the handle causing injury to the user or bystanders. Additional difficulties may occur even if the head does not come off the handle since a loose connection of the head may cause an inefficient use of the tool and could cause injury to the user. An additional common problem is vibration through the handle. On a large tool especially, the impact through the head can create a lot of vibration in the handle. Wood is commonly used as the handle material since it helps to dampen the vibration. The vibration through the handle can be effected by the manner in which the head is mounted on the handle, and especially can be decreased by a good tight fit of the head on the handle.
In order to obtain a tight fit between the head and the handle, a number of different types of wedges have been developed U.S. Pat. No. 1,914,082 shows a sleeve which fits between a pick head and a handle. The sleeve is resilient and compressed slightly as the head is forced onto the handle. The sleeve may be formed in two pieces connected by a strip which protects the end of the handle.
U.S. Pat. No. 3,669,512 shows a carpenter's hammer which is held on a handle by means of a wedge. This wedge is formed in two directions. That is, the wedge forms a cross shape when viewed from the end of the handle. Thus, the spreading action of the wedge occurs in two perpendicular directions.
U.S. Pat. No. 1,518,259 also shows a carpenter's handle with a wedge in two directions. In this case, a long bolt extends through the handle of the hammer in order to hold the wedge in place. Unfortunately, the presence of such a metal object in the handle may badly effect the vibration damping facility of the wood handle.
German Patent 3041531 to Becker shows a handle connection for a hammer with a plate that fits on a ledge surrounding an eye near the upper surface of the head. A screw fits through a small opening in the plate and is screwed into the handle. However, in this system if the handle is short, some movement of the handle in the head occurs upon impact even if the plate is screwed tightly to the handle. Also, if the handle is too narrow because of shrinkage due to drying, for example, the handle may become loose and rattle. Such movements not only cause undesirable vibrations but also can shorten the life of the handle.
While these and similar devices help to hold tool heads on handles, they are subject to loosening and may undesirably effect the vibrational characteristics of the handle.